Method and apparatus for molding hollow rings of rubber or the like



March 29, 1932. J. R. FOLEY 1,851,505

METHOD AND APPARATUS FOR MOLDING HOLLOW RINGS OF RUBBER OR THE LIKE Filed May 20, 1950 2. Sheets-Sheet 1 HIM!!! zz gmentov cfoimfLfble y J. R. FOLEY 1,851,505

METHOD AND APPARATUS FOR MOLDING HOLLOW RINGS OF RUBBER QR THE LIKE March 29, 1932.

Filed May 20, 1950 2 Sheets-Sheet ya wanton eIOM 1'?) leg Patented Mar. 29, 193 2 UNITED STATES PATENT OFFICE JOHN RUSSELL FOLEY, OF NEW YORK, N. Y.

METHOD AND APIPARATUS For. MOLDING noLLow RINGS" on RUBBER on THE LIKE Application filed May 20,

This invention relates to improvements in methods and apparatus for molding hollow rings of rubber or the like, and while the invention has been developed specifically for the'making of swimming rings or circular life preservers, it will be manifestto those skilled in the art that it may be .used in the manufacture of inner tubes for tires or the like.

In accordance with the invention, a helical or spherical mandrel is detachably mounted upon a revolving shaft, and while the mandrel is rotated with the shaft, the lower portion of the mandrel is dipped into fluid latex, so as to completely cover the mandrel with such plastic material, andafterwards, the rotating mandrel is either raised, or the latex tank is lowered to such an extent that the mandrel in its subsequent rotation, will dip only partially intothe plastic material, and in this way, the peripheral portion of the molded ring may be thickened. Afterwards, the

vmolded tube is out along certain radial lines,

to facilitate the detachment of the mandrel from its rotatable'support, and then the tube may be stripped from the mandrel, and the ends of the tubefmay be overlapped. and secured together to form a swimming ring-or the like. I

. A salient object of theinvention is to provide an improved method and apparatus for molding rubber rings or the like in the manner above set forth.

- With the foregoing objects outlined and with other objects in view which will appear as the description proceeds, the invention consists in the novel features hereinafter'described in detail, illustrated in the accompanying drawings, and more particularly pointed out in the appended claims.

In the drawings, r ,7 Fig. l is a side elevation, partly in section, of the improved mandrel and its support. -Fig. 2is a similar view with the forward end portion of the mandrel cut away to illustrate the manner in which the rear end portion of the mandrel is secured to the rotatable support. a

edge view ofthe mandrel. V Fig. l is amore or less diagrammatic view 1930. Serial No. 454,103. I

of one form of the complete apparatus.

' Referring to the drawings, 5'designates a rotatable shaft which is mounted in vertically adjustable bearings 6,'that are supported by standards! ,and may be secured in adjusted positions, by any suitable means, such as bolts 8. The shaft may be driven by any suitable means, through the instrumentality of a gear 9' which is mountedon the shaft. l A hub 10 rotates with the shaft and is provided with two arms 11 and 12 which project from the shaft'in the samegeneral direction, but diverge outwardly, as shown in Figs. l and 2. I

Each arm or spoke is provided at its outer end'with a collar 13 having a ferrule 14 to receive the shank of a screw 15. The head of each screw is preferably of conical form, as shown at 1 6, and is provided with. a groove 17 to receive a screw-driver or the like.

These screws are designed to be connected to threaded sockets 18 which are securedto the offset overlappingends of the helical mandrel 19, by any suitable. means, such as screws 20. This construction allows themandrel to be rigidly supported by the rotatable shaft, with the mandrel concentric to the axis Y of the shaft.

The mandrel may tliesame of circular cross section. V An arm 21 projects from the hub ina di may be dip'ped into anysuitable plastic fluid r r i in, atank 24. The dippingmay be'accom be ofany suitable shape clrcumferentially,but, it is preferred to have ,rection opposite to thearms 1'1 and 12, and

'plished' by means ofthe bearings 6,' that'1is, V

such bearings maybe-lowered to cause the lower portion of therotatingmandrel to be completely submerged in the plastic material,

and then thebearingsmay be fixed injthis, j

position by the bolts theother hand, if I desired, instead of lowering the shaft 5, the

tank 24 may be elevated by any suitable means for this purpose. For example, the tank may be raised by means of a foot lever 25, which is pivotally mounted at 26 on one of the standards 7. Guides 27 may be used to'guide the tank in its vertical movements.

After the shaft has been rotated for a sufficient length of time to completely submerge the lower portion of the mandrel in the plastic material to deposit one or more coats on the mandrel, theshaftmay be'ra-i'sed, or the tank may be lowered so as topermit'onlya part of the lower portion of the mandrel to be dipped into the plastic material during the rotation of the mandrel, for the purpose of increasing the thickness of the coat on the peripheral .portion'of the mandrel. In this way,

' a shaped circularrubber tube may be made by theso-called latex dip. process.

The invention has been evolved as a result of determining an economical -manner of manufacturing swimming. rings or circular life-.preservers. .Its development, while .perfecting and, making p'racticalthe manufacture of such articles, at the same time ems its rotating support.

the. parts 5 or 24 has been moved relatively ends of the mandrel overlap.circumferentially, the ends of the rubber tube may also be" bodies a 'very feasible method for jmanu-facturing innertubes, and regardlessof the pur- I pose for which it is used, after therubber tube has'been molded on the mandrel, either'the shaft 5 is raised, or the tank 24 is lowered to allowthe'detachment of themandrel from After either one of to the other, to permit the detachment of the mandreh'the'rubber is severed along the-lines 'A B 'and-CD, and then the ends of the rubber tubew'hichj enclose the parts 18 and 16, are strippedirom the ends of the mandrel.

Then the screws are removed to disconnect the ends oflthe mandrel from the collars13, and the mandrel i s detached "from .itsrotatable support. Of course, afsimilar 'mandrel can immediately be attached to the rotatable support for a subsequentmolding operation. a After thecoated mandrel is removed,v the rubber tube is. stripped therefrom, and asthe "overlapped and be "secured together by vul-' canizingor the like, for thepurpose of forming a complete swimming ring orilike article.

I Inpractice, after the mandrel has. been 7 mounted on its rotatable support, the next step is to pass the'mandrel, while revolving,

through ;liqu id latex, for the time necessary submerged inthe latex, while'the remainder l ng fof the mandrel is ilex'p'o'sed "to atmosphere.

When sufiicient latex for the purpose has adhered to the mandrel, the complete submersion will be terminated by either lifting the mandrel as a whole, or lowering the latex solution. The revolving of the mandrel on its axis is continued until such time as the latex on it has become set or fixed; Y 7

Due to the rotation of the mandrel, the socalled drops or ridges'created by liquid latex are eliminated. I I e In: order-that the-air valve may be attached to the ring after thelatter is molded, the mandrel is provided near one of its ends with a. projecting post 50, and theopposite end portion of the mandrel is furnished with a cavity- 51 Consequently, whilethe ring'is being molded.,";anaperture will be providedin the same where the pin is located,and ca thicl-zened portion will be provided where the cavity 51 is positioned n Then, afterthe ring is stripped from the mandrel, and its ends are overlapped, the air val-ve'may beattached at the points where the thickened portion registers with the aperture. From the foregoi-ng i-tis believed that zthe invention maybe readily understood bythose skilled in the *art, -a nd it is apzparentathat changesmay be made in the details disclosed,

without departing from the spiritof the invention, as expressed in the claims.

What is claimed-and desired to be secured byLetters Patent 1s;

1. A- method of; manufacturing ,circular' tubes comprising rotating a helical mandrel i about a hori'zontal axis while the lower sec tion of. the mandrel is substantially sub"- merged in a pool of a rubbersolution,.andlthe 7 remaining iportion. ofthe same is above the ipool and in the 1 atmosphere, continuing'the rotation of the mandrel until -'a:coat of the from the mandrel and overlapping andrconnecting the ends of saidtube.

A method-as claimedfinclaim"1,? in

.whiehlthe mandrel issubmerged in the: pool to varying degrees during-the rotation'of the mandreh to, provide a thicker coat of the? rubher I SOlLltlOD-Dll certain portions of the mandrel; p f I An apparatus ofthecharacterdescribed,

comprising a helical mandrel member, a sup port for the mandrel rotatable about Ya-cherizontal axisfa tank member adapted toxeontain I a rubber solution into whiehith'e mandrelldips :rubber solution-ofthe desired-thickness is de- .positedon themandrel, and afterthe-coating *haS'SBt, strrppmgthe resultingmubber.tube

while rotating-,jand means for moving one of' said membe'rs toward or a-wayfromtheio-ther inemoer for varyiiiggthe depth of submer'sion of the mandrel -in the-q'iool of solution con-- 'tained in the tank-J2 4. Anapparatnsoftlre character described, 1

including rotatable supporting means, a eli cal mandrel, and"means for detachablyrcon cal mandrel, and screws detachably connect ing the ends of the mandrel to the supporting means.

7. A rubber ring molding apparatus, including rotatable supporting means, a helical mandrel, screws detachably connecting the ends of the mandrel to the supporting means, and counter-balancing means connected to the supportingmeans for counterbalancing the mandrel.

8. A rubber ring molding apparatus, comprising a rotatable shaft, arms projecting adjustably mounted on the third arm for counter-balancing said mandrel.

14. An apparatus of the character described, comprising a hub rotatable about a horizontal axis, diverging arms movable with s and projecting from said hub, rings con-.

nected to the outer ends of the arms, a helical mandrel arranged concentrically to said axis, and having ofiset overlapping ends, a threaded socket secured to each end of the mandrel, and threaded fastening devices passing through said rings and engaging said sockets for detachably connecting the-mandrel to said rings. 7

In testimony wherof, I have signed this specification.

JOHN RUSSELL FOLEY.

from the shaft, a helical mandrel concentric with the axis of the shaft, and means detachably connectingtheends of the mandrel to 7 said arms.

9. A rubber ring molding apparatus comprising a rotatable shaft, diverging arms proj ecting from the shaft, a helical mandrel concentric with the axis of said shaft, and means for detachably securing said arms to the ends of the mandrel. r

.10. A rubber ring molding apparatus comprising a rotatable shaft, diverging arms projecting from the shaft, a helical mandrel arranged concentrically to the axis of the shaft, and having ofiset overlapping ends, and means detachably connecting the outer ends of the arms to the ends of the mandrel.

11. A rubber ring molding apparatus, comprising a rotatable shaft, diverging arms centrically to the axis of said shaft and hav-. 7

' ing overlapping ends, and'screws detachably connecting the ferrules to the ends of the mandrel. 1

12. An apparatus of theccharacter described, comprising means rotatable about a horizontal axis, diverging arms movable with and projecting from said means, a helical mandrel arranged concentric to said axis and having overlapping ends, and quick detachable means joining said arms to the ends of y the mandrel. V

13. An apparatus of the character described, comprising means rotatable abouta horizontal axls, diverging arms movable with and projectingfrom said means, a helical mandrel arranged concentric to said axis and having overlapping ends, quick detachable means joining said arms to the ends of the mandrel, a third arm projecting from the first mentionedmeans in a direction opposite to that of the diverging'arms,and'a weight 

